One of the needs in the technique of isotope separation employing laser beams to produce isotopically selective photoexcitation and ionization is the multiplexing (including combining and/or decombining) of pulsed beams of laser radiation between a common path of high pulse rate and plural distinct paths of relatively lower pulse rate having the pulses distributed amongst the separate paths according to some predetermined sequencing pattern. Such a multiplexing function is desirable to distribute the output of a master oscillator laser operating at a high pulse rate and at a frequency to produce isotopically selective photoexcitation or ionization onto a plurality of distinct separate paths, the radiation of which is amplified in one or more stages. It is desired to employ the output of a single master oscillator to insure wavelength consistency in each amplifier stage, but it is similarly desirable to distribute separate pulses and to thus reduce the pulse rate before amplification to apply the full intensity of each pulse to the amplifiers at a low rate commensurate with high power amplification.
It is also desirable that pulsed radiation paths of relatively low pulse rate be ultimately combined into substantially higher pulse rate beams for application to the uranium vapor where isotopically selective photoexcitation or ionization is accomplished.